PEF2256 INFINEON [Infineon Technologies AG], PEF2256 Datasheet - Page 251

• Manufacturer Part Number: PEF2256
• Description: E1/T1/J1 Framer and Line Interface Component for Long- and Short-Haul Applications
• Manufacturer: INFINEON [Infineon Technologies AG]

Transmit Pulse Mask (Read/Write)
Value after reset: 7B
XPM0
XPM1
XPM2
The transmit pulse shape which is defined in ITU-T G.703 is output on pins XL1 and XL2.
The level of the pulse shape can be programmed by registers XPM(2:0) to create a
custom waveform. In order to get an optimized pulse shape for the external transformers
each pulse shape is internally divided into four sub pulse shapes. In each sub pulse
shape a programmed 5 bit value defines the level of the analog voltage on pins XL1/2.
Together four 5-bit values have to be programmed to form one complete transmit pulse
shape. The four 5-bit values are sent in the following sequence:
Changing the LSB of each subpulse in registers XPM(2:0) changes the amplitude of the
differential voltage on XL1/2 by approximately 90 mV. Setting of LIM2.EOU causes the
values of XP20...23 and XP30...33 to be negative.
Example: 120
Programming values for XPM(2:0): 00
User’s Manual
Hardware Description
XP12
XP30
7
0
interface and wired as shown in
XP11
XP24
XP04 to 00:
XP14 to 10:
XP24 to 20:
XP34 to 30:
XP04 to 00:
XP14 to 10:
XP24 to 20:
XP34 to 30:
XLT
H
, 03
H
, 40
DAXLT
XP10
XP23
H
First pulse shape level
Second pulse shape level
Third pulse shape level
Fourth pulse shape level
1C
1C
00
00
H
H
H
H
XP04
XP22
H
or 28 decimal
or 28 decimal
, 03
0
251
H
, 9C
XP03
XP21
XP34
H
Figure 54
XP33
XP02
XP20
on
page
XP01
XP14
XP32
160.
DS1.1, 2003-10-23
PEF 2256 H/E
XP00
XP13
XP31
E1 Registers
0
FALC
(26)
(27)
(28)
®
56